Adding HPA for eventing-webhook:

- Scale Webhook based on CPU
- Add initial PodDisruptionBudget

Signed-off-by: Matthias Wessendorf <mwessend@redhat.com>

config/core/deployments/webhook-hpa.yaml

@@ -0,0 +1,51 @@
+# Copyright 2020 The Knative Authors
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+apiVersion: autoscaling/v2beta1
+kind: HorizontalPodAutoscaler
+metadata:
+  name: eventing-webhook
+  namespace: knative-eventing
+  labels:
+    eventing.knative.dev/release: devel
+spec:
+  minReplicas: 1
+  maxReplicas: 5
+  scaleTargetRef:
+    apiVersion: apps/v1
+    kind: Deployment
+    name: eventing-webhook
+  metrics:
+    - type: Resource
+      resource:
+        name: cpu
+        # Percentage of the requested CPU
+        targetAverageUtilization: 100
+
+
+---
+
+# Webhook PDB.
+apiVersion: policy/v1beta1
+kind: PodDisruptionBudget
+metadata:
+  name: eventing-webhook-pdb
+  namespace: knative-eventing
+  labels:
+    eventing.knative.dev/release: devel
+spec:
+  minAvailable: 80%
+  selector:
+    matchLabels:
+      app: webhook

config/hpa-webhook.yaml

@@ -0,0 +1 @@
+core/deployments/webhook-hpa.yaml